Correlations (Spearman ϱ) between plasma phosphatidylcholine n-3 and n-6 fatty acids (μg/ml) at baseline, Week 12, and the averaged concentration from both timepoints, with change in DAS28 score following 12 weeks of anti-TNF therapy. Long-chain n-3 PUFA were considered 20:5n-3 (EPA), 22:5n-3 (DPA), and 22:6n-3 (DHA). Product to precursor ratios were used to estimate the activity of the Δ5 (20:4n-6/20:3n-6) and Δ6 (18:3n-6/18:2n-6) desaturases.
| Plasma Fatty Acids | Correlation of Plasma Fatty Acids with Change in DAS28 (p value) | ||
|---|---|---|---|
| Baseline | Week 12 | Mean | |
| 18:2n-6 | 0.408* (0.03) | −0.117 (0.30) | 0.125 (0.29) |
| 18:3n-6 | 0.031 (0.45) | 0.211 (0.17) | 0.162 (0.24) |
| 18:3n-3 | 0.138 (0.27) | 0.216 (0.17) | 0.162 (0.24) |
| 20:2n-6 | 0.181 (0.21) | −0.158 (0.24) | 0.013 (0.48) |
| 20:3n-6 | 0.072 (0.38) | 0.034 (0.44) | 0.067 (0.38) |
| 20:4n-6 | 0.029 (0.45) | 0.062 (0.39) | −0.001 (0.50) |
| 20:4n-3 | 0.072 (0.38) | −0.303 (0.09) | −0.186 (0.20) |
| 20:5n-3 | −0.324 (0.07) | −0.394* (0.04) | −0.513** (0.007) |
| 22:4n-6 | 0.132 (0.28) | −0.068 (0.38) | 0.050 (0.41) |
| 22:5n-3 | 0.043 (0.42) | −0.368* (0.046) | −0.269 (0.11) |
| 22:6n-3 | −0.137 (0.27) | −0.113 (0.31) | −0.167 (0.23) |
| Total n-3 PUFA | −0.187 (0.20) | −0.360 (0.05) | −0.366* (0.047) |
| Total long-chain n-3 PUFA | −0.190 (0.20) | −0.373* (0.04) | −0.425* (0.02) |
| Total n-6 PUFA | 0.301 (0.09) | −0.066 (0.39) | 0.144 (0.26) |
| n-3/n-6 PUFA | −0.435* (0.02) | −0.178 (0.21) | −0.363* (0.048) |
| EPA/AA | −0.234 (0.15) | −0.535** (0.005) | −0.478* (0.01) |
| Δ5 desaturase activity | 0.001 (0.50) | 0.128 (0.29) | 0.058 (0.40) |
| Δ6 desaturase activity | −0.241 (0.14) | 0.047 (0.42) | −0.125 (0.29) |